PURPOSE: The ConfoScan 3 clinical confocal microscope provides sharper images of cells in the stroma than the Tandem Scanning confocal microscope does. In this study, we compared volumetric densities of stromal cells determined from images recorded by these two instruments. METHODS: Fifty corneas of 25 normal subjects were examined by ...

In this study, we identify the extent of deformation that causes cell lysis using a simple technique where a drop of cell suspension is compressed by two flat plates. The viability of human prostatic adenocarcinoma PC-3 cells in solutions of various concentrations of NaCl is determined as a function of ...

The Cl(-)/HCO3- exchanger (AE) is one of the mechanisms that cells have developed to adjust pH Despite its importance, the role of AE isoforms in controlling steady-state pH during alkalosis has not been widely investigated. In the present study, we have evaluated whether conditions simulating acute and chronic metabolic alkalosis ...

Partial pressure of CO2 (pCO2) and osmolality as high as 150 mmHg and 440 mOsm/kg, respectively, were observed in large-scale CHO cell culture producing an antibody-fusion protein, B1. pCO2 and osmolality, when elevated to high levels in bioreactors, can adversely affect cell culture and recombinant protein production. To understand the ...

The polarized distribution of Na+,K+-ATPase plays a paramount physiological role, because either directly or through coupling with co- and countertransporters, it is responsible for the net movement of, for example, glucose, amino acids, Ca2+, K+, Cl-, and CO3H- across the whole epithelium. We report here that the beta-subunit is a ...

The default framework for modeling biochemical processes is that of a constant-volume reactor operating under steady-state conditions. This is satisfactory for many applications, but not for modeling growth and division of cells. In this study, a whole-cell modeling framework is developed that assumes expanding volumes and a cell-division cycle. A ...

We investigated the phytoplankton in the central area of the Venice lagoon in the 1990s. Water samples were collected at 46 sites in June 1993 and June 1998 and at four stations every month from November 1998 to October 1999. Collected data include community composition, cell abundance, and cell bio-volumes, ...

Concanamycin A and bafilomycin A are well-known inhibitors of V-ATPase activity. It is known that they interfere with intracellular protein trafficking in both animal and plant cells, but a cellular target for their action in plant cells has not been defined. Here we show that treatment with these inhibitors leads ...

All cells face constant challenges to their volume either through changes in intracellular solute content or extracellular osmolality. Cells respond to volume perturbations by activating membrane transport and/or metabolic processes that result in net solute loss or gain and return of cell volume to its normal resting state. This paper ...

Bestrophins are a newly identified family of Cl(-) channels. Mutations in the founding member of the family, human bestrophin-1 (hBest1), are responsible for a form of early onset macular degeneration called Best vitelliform macular dystrophy. The link between dysfunction of hBest1 and macular degeneration remains unknown. Because retinal pigmented epithelium ...

The Surface Evolver was used to compute the equilibrium microstructure of dry soap foams with random structure and a wide range of cell-size distributions. Topological and geometric properties of foams and individual cells were evaluated. The theory for isotropic Plateau polyhedra describes the dependence of cell geometric properties on their ...

Antennal gustatory sensilla of the ground beetle Pterostichus aethiops (Pz., 1797) (Coleoptera, Carabidae) respond to salts, the three sensory cells, A-, B- and C-cells, producing action potentials that are distinguished by differences in their shape, amplitude, duration and polarity of spikes. The B-cell (salt cell) was highly sensitive to both ...

The objective of this study was to assess estrogen-dependent cellular mechanisms that could contribute to the acid pH of the vaginal lumen. Cultures of normal human cervical-vaginal epithelial (hECE) cells and endocervical cells were grown on filters, and acidification of the extracellular solutions on the luminal (L-pHo) and contraluminal (CL-pHo) ...

Investigating the intracellular contents of single cells is essential for understanding physiologic and pathologic processes at the cellular level. While existing protocols for cell lysis and sample preparation work well for larger samples, scaling to a single-cell level is challenging because of unavoidable analyte dilution and losses. Thus, we are ...

BACKGROUND: The Na(+)/H(+) exchanger (NHE) of mammalian cells is an integral membrane protein that extrudes H(+) ion in exchange for extracellular Na(+) and plays a crucial role in the regulation of intracellular pH (pHi). Thus, when pHi is lowered, NHE extrudes protons at a rate depending of pHi that can ...

Red blood cells of marine fish have been used in suitable biological assays to study the (eco)toxicity of wastewater treatment plant effluents. The aim of the present work was to draw upon their more relevant effects on cell hemolysis, ATP content, osmotic resistance and cell volume regulation. Following physico-chemical treatment, ...

It is desirable that cells adsorbed in affinity-separation processes be easily recovered from the adsorption surface, without excessive dilution, once contaminants have been removed. The present study investigates the use of gas-bubble-induced shear stress for the recovery of affinity-adsorbed human erythrocytes. This method has previously been demonstrated to be effective ...

The occurrence of cell lysis following exposure to ultrasound (US) has been well documented; the specifics of the mechanistic process(es) involved have proven to be difficult to characterize. There appear to be two major mechanisms of US-induced cell lysis in vitro, acoustic cavitation and bubble transport. Both involve shear forces. ...

Stereological methods were used to quantify secretin and gastric inhibitory peptide (GIP)-immunoreactivity (GIP-IR) in paraffin sections of the duodenum, jejunum and ileum of fetal and neonatal piglets. In addition, sections were processed for GLP-1-immunohistochemistry. The volume density of the tunica mucosa increased after birth, giving rise to a decreased volume ...

Many cells exhibit disparate responses to a mechanical stimulus depending on whether it is applied dynamically or statically. In this context, few studies have examined how cells respond to dynamic changes of the extracellular osmolality. In this study, we hypothesized that the cell size change response of cultured articular chondrocytes ...

It is proved that the shape of the typical cell of a stationary Poisson-Voronoi tessellation in Euclidean space, under the condition that the volume of the typical cell is large, must be close to spherical, with high probability. The same holds if the volume is replaced by the surface area ...

Lampreys, one of the only two surviving groups of agnathan (jawless) vertebrates, contain several anadromous species that, during their life cycle, thus migrate from fresh to seawater and back to freshwater. Lampreys have independently evolved the same overall osmoregulatory mechanisms as the gnathostomatous (jawed) and distantly related teleost fishes. Lamprey ...

To study the role of Magnesium in the regulation of cell proliferation we characterized the proliferation behaviour of HC-11 mammary epithelial cells that were grown in media containing low to high Mg concentrations. Cells grown under control conditions (0.5 mM Mg in the medium) or in the presence of high ...

The response of murine macrophages to clinically relevant polyethylene wear particles generated from different polyethylenes at various time points and volumetric doses in vitro was evaluated. Clinically relevant ultra high molecular weight polyethylene (UHMWPE) wear debris was generated in vitro in a lubricant of RPMI 1640 supplemented with 25% (v/v) ...

This article is a review highlighting the application of the acoustic filter as a reliable cell retention device during the long-term perfusion of animal cell cultures. Critical operating parameters such as duty cycle, perfusion and re-circulation flow rates, acoustic power and backflush frequency are discussed with regard to influence on ...

By virtue of their electroneutral exchange of intracellular H+ for extracellular Na+, the Na+/H+ exchangers (NHE1-NHE8) play a pivotal role in many physiological processes. This review focuses on the ubiquitous plasma membrane isoform, NHE1. Particular attention is given to the roles and regulation of NHE1 in erythrocytes, in their own ...

The haematological changes observed with commercially available haematinics (Fagon 9? and Chemiron?) were compared with those of a local haematinic referred to as African Herbal Formula (AHF). Results showed that AHF produced effects in haemoglobin (Hb) and packed cell volume (PCV) levels, which are reasonably comparable with the reference commercial ...

AIM: Colonic epithelium is known to secrete both Cl(-) and HCO(3)(-), but the secretory mechanisms of different colonic cell types are not fully understood. The present study aimed to investigate the differential activation of Cl(-) and HCO(3)(-) secretion by tetramethylpyrazine (TMP) in human crypt-like cell line, T84, and villus-like cell ...

this paper, we adopt #"2, which implies a quadratic e!ect of enzymes. This speci"c choice of a quadratic e!ect is not essential in our model of cell di!erentiation. Furthermore, we take into account the change in the volume of a cell, which varies as a result of the transportation of ...

Rat lactotrope cells in primary cultures have a higher intracellular Cl- concentration ([Cl-]i) than that predicted by a passive distribution across the membrane. This suggests that active cellular mechanisms ensure this ionic equilibrium. In this study, we examined the interactions between pHi, [Cl-]i regulation and cell energetics. We analyzed: 1. ...

Cholesteryl butyrate solid lipid nanoparticles (chol-but SLN) have been proposed as a pro-drug to deliver butyric acid. We compared the effects on cell growth, cell-cycle distribution and c-myc expression of chol-but SLN and sodium butyrate (Na-but) in the human leukemic cell lines Jurkat, U937 and HL-60. In all the cell ...

In response to osmotic cell swelling, Intestine 407 cells react with a rapid and transient activation of phospholipase D (PLD). To investigate the role of PLD during the regulatory volume decrease, cells were treated with 1-butanol resulting in a depletion of PLD substrates. Activation of volume-regulated anion channels, but not ...

Na+/H+ exchangers (NHE) are widely distributed transporters responsible for regulation of cell volume and pH. In isotonic medium, NHE is often low or negligible, and is strongly activated by osmotic cell shrinkage. It is reported here that extracellular Na+ inhibits NHE in isotonic medium, and cell shrinkage stimulates NHE by ...

Li Rena R Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, KY 40292, - - 2004

While the pathogenesis of manic-depressive, or bipolar, illness is unknown, an excess of intracellular sodium and calcium concentrations is thought to contribute to the development of the illness. Previous work has demonstrated a reduced adaptive response of the sodium pump to ethacrynic acid in lymphocytes obtained from bipolar subjects compared ...

The immunofluorescence approach, the confocal microscopy and the patch-clamp technique were used to investigate the expression of ClC-3 (one of the candidates of volume-activated chloride channels) and its relationships with the volume-activated chloride current and the capacity of regulatory volume decrease (RVD) in the cell cycle of nasopharyngeal carcinoma cells ...

In this article, we examine a large number of combinations of growth models, with separate attention to cell volume, cylindrical surface-area, polar caps, nascent poles, onset of constriction, precision of cell division and interdivision-time dispersion, for Escherichia coli cells growing in steady state at various doubling times. Our main conclusion ...

In this paper we present a novel hybrid CPU-GPU approach for rendering curvilinear grids. Visibility sorting is accomplished by parallel peeling cells off the grid, utilizing an active cell peeling front. In each step, we compute the ray-cell intersection coordinates on the GPU, perform accurate volume integration (CPU), and determine ...

Abstract. In previous work we described a "P-->A mechanism" that transduces occupancy of the pump ( P) by ouabain into changes in phosphorylation, stimulation of mitogen-activated protein kinase (MAPK), and endocytosis of cell-cell- and cell-substrate-attaching molecules ( A), thereby causing a release of the cell from the monolayer. In the ...

Previously, we demonstrated that malignant glioma cell lines have increased intracellular pH (pHi) as a result of increased activities of the type I sodium/hydrogen exchanger (NHE1). This alkalotic pHi of 7.2 to 7.4 is favorable for augmented glycolysis, DNA synthesis, and cell cycle progression. Conversely, reductions in pHi have been ...

Treatment of cerebral cortical slices with 5mM ammonium acetate (ammonia) elevated the glutamine (Gln) content and increased cell volume in the slices, in agreement with the postulated contribution of glutamine to hyperammonemic brain edema [Neurochem. Int. 43 (2003) 299]. In this study we show that, unexpectedly, treatment with a glutamine ...

The membrane protein KCNE1 has been implicated in cell volume regulation. Using a knockout mouse model, this study examined the role of KCNE1 in regulatory volume decrease (RVD) in freshly isolated renal proximal tubule cells. Cell diameter was measured using an optical technique in response to hypotonic shock and stimulation ...

1. There are no effective ways of screening for potential modulators of volume-regulated anion channels in their native cell type. Generally, cell lines are used for this purpose. Using HeLa and C6 glioma cells, we identified the pyrethroids as a novel class of compounds that inhibit taurine efflux through volume-regulated ...